Bridging the gap between CMOS and QCA: The integration of single electron devices and CMOS technology.

摘要

As CMOS nears the end of scaling, the electronics industry is looking to alternatives to CMOS for high speed operation with low power computation. The use of Single Electron Transistors (SETs) in conjunction with advanced technologies such as Quantum-dot Cellular Automata (QCA) may provide an avenue for increased computational capabilities beyond the CMOS paradigm. It is likely that future high performance computers will utilize alternative technologies such as QCA and SETs for high speed computation, due to the prohibitive energy demands of CMOS. However, the advantages of CMOS cannot be ignored. It is a well-understood, mature technology that is adequate in the majority of its current uses. CMOS will continue to be used in applications that require lower speed, including input and output systems for even the most advanced computers using alternative technologies. Therefore, in order to harness the abilities of SET/QCA architectures, it is imperative to develop integration between SETs and CMOS architectures.;This thesis presents a proof-of-concept integration of CMOS, SETs, and QCA. A CMOS input system has been designed and fabricated to allow CMOS logic-level signals to be used as control signals for a QCA cell. The state of the QCA cell is read using SET electrometers. Two different CMOS voltage amplifiers were designed and fabricated to allow amplification on the SET signal: A CMOS linear amplifier, and a CMOS inverter, which provides gain with no external components. In both cases the amplifier was coupled to an SET co-located on the same substrate. Since the SET must operate at temperatures less than 4.2K, the CMOS amplifier must also operate at this temperature.;Testing of the linear amplifier demonstrated the amplification of the SET voltage output. Coulomb blockade and Coulomb blockade oscillations were observed with this amplifier. The CMOS inverter was also able to amplify the output of the SET, and again both coulomb blockade and Coulomb blockade oscillations were visible through the amplifier. SET instability resulting from the use of the CMOS devices was observed. Despite the instabilities, a proof-of-concept demonstration of the use of CMOS and SETs together has been achieved, and new avenues of research that may lead to more complete CMOS-QCA integration have been opened.